<script setup>
import { ref } from 'vue'
const num = ref(999)
defineExpose({
  num
})
</script>

<template>
  <div class="son-page">son---{{ num }}</div>
</template>

<style scoped>
.son-page {
  width: 300px;
  height: 300px;
  border: 5px solid red;
}
</style>
